“”It is remarkable how fast and how effectively you can construct a nationality with a flag, a few speeches, and a national anthem.

—Nicholas Nassim Taleb, The Black Swan: The Impact of the Highly Improbable

A nation (often interchanged with country) is a group of people who share certain characteristics in common, most commonly language, religion, ethnicity, and history. As a sociological and political term, it is a fluid concept — what Benedict Anderson has termed an "imagined community."[1] It has been common in history for different nations to fuse together[2] or for a single nation to break apart.[3] Sometimes, a single person may feel they belong to more than one "nationality", depending on circumstances.[4]

Most of the states of WesternEurope were built along national lines - Denmark, Malta and Iceland, for example; but compare Austria, Ulster, Switzerland, Catalonia, San Marino, Belgium, Luxembourg, Cyprus, Alsace-Lorraine, the Vatican City and the United Kingdom of Great Britain and Northern Ireland. However, nation-building also came about due to European monarchs fostering a sense of nationhood amongst their peoples, through nationalism, the adoption of the "vulgar" languages, and concentrated myth-making.[5]
Since the end of World War I, nationality as the primary pre-requisite for statehood has declined. Today, most states are rather multi-national[6] though there was a brief resurgence of "ethnic group gets a country" in the 1990's with the break up of the communist system in Eurasia.